In order to actuate such an accelerator device, an actuation force generally has to be applied to the accelerator device. For example, an accelerator pedal must be depressed with the foot, or a twist-grip throttle must be rotated with the hand. If the applied actuation force is sufficiently large, the accelerator device is deflected from a rest position. The degree of the deflection is communicated mechanically or electronically to an engine control unit and converted there into a corresponding engine load or desired power output.
Usually, the accelerator devices described above include means which cause a restoring force to act upon the accelerator devices. The restoring force hereby generally acts counter to the actuation force and in the direction of the starting position of the accelerator device. For example, such a restoring force can be caused by a spring mechanism or electrically by a torque motor which is coupled with the accelerator device. Common restoring mechanisms are configured such that the restoring force is constant over the entire deflection range or increases towards greater deflections of the accelerator device.
The deflection of the accelerator device from the rest position can be described by a deflection angle φ. For example, the deflection angle φ can be defined such that the deflection angle φ is equal to zero for the rest position of the accelerator device, whilst the deflection angle for a maximum deflection of the accelerator device is defined as a fixed value. The deflection of the accelerator device can, for example, also be described as a percentage of the maximum deflection. The starting position of the accelerator device corresponds to a deflection of 0%, whilst the maximum deflection of the accelerator device, which is also described as “full throttle”, corresponds to a deflection of 100%.
Based on a distance detected by a driving environment sensor, traditional adaptive cruise control systems intervene, if necessary, in the engine control, control the fuel supply in particular and thus, ultimately, control the engine speed and torque of the engine directly and without taking into account or even influencing the position of the manual accelerator device such as the accelerator pedal or the twist-grip throttle.
In addition, WO 2005/105508 already describes the process, with a so-called force feedback pedal, i.e. an accelerator device having a restoring device, of actively influencing the position of the accelerator device which then, of course, also indirectly acts upon the engine control.
In addition, in DE 10 2010 031 080 A1, a controller concept for a device for generating a restoring force on an accelerator pedal is presented, in which a separate controller is provided, in each case, for different operating situations, in particular when following another vehicle as well as for deceleration. Separate controllers make it possible to individually adjust the parameters of the controller and, thus, the latter's control behavior to the respective operating situation, but increase the complexity and expense, even if nowadays controllers are frequently constructed as a software control system, since memory space and computing time also have to be considered in software.